Perhaps you should try some spelling variations:
sach ty » sach y, sach tu, sach thu
tao cao » bao cao, toan cao
tai cao » thai cao, tai sao, tai cac
va vanh » va van, va danh, va hanh
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
ty lang » tay lang, ty xang, ty hang
va cao » va co, va dao, va bao
luc va » duc va, tuc va, loc va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ty lang xa hoi. hieu ((va cac) or (va cao)) luc va vanh ((tai cao) OR (tao cao)) trieu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty lang xa hoi. hieu ((va cac) OR (va cao)) luc va vanh ((tai cao) OR (tao cao)) trieu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty lang xa hoi. hieu ((va cac) or (va cao)) luc va vanh ((tai cao) OR (tao cao)) trieu".
• Adding a wildcard symbol may retrieve word variants: tu sach ty lang xa hoi. hieu ((va cac) or (va cao)) luc va vanh ((tai cao) OR (tao cao)) trieu*.